1. Field of the Invention
The present invention relates to a solid pharmaceutical preparation, especially a buccal dissolution type solid preparation having characteristics of fast disintegration or dissolution in the oral cavity even without water.
2. Description of Related Art
Generally, solid pharmaceutical preparations such as tablets are designed so that after they are orally administered, they disintegrate or dissolve in the digestive organs and the pharmaceutically active ingredients are absorbed. Accordingly, fast disintegration or dissolution in the oral cavity is not a common design feature.
However, in accordance with the increase in the aged population and change in life styles, there has been a need for development of buccal dissolution type solid preparations which can be, if necessary, administered readily even without water, by aged people and children anywhere or anytime, maintaining the convenience typically afforded by pharmaceutical tablets.
As the technique for producing preparations which quickly disintegrate or dissolve in the oral cavity, heretofore, there has been proposed a method for producing preparations by dissolving or suspending pharmaceutical or medicinal ingredients in an aqueous solvent, filling the resultant solution or suspension into a pocket molded beforehand in a blisterpack and reducing water content from the solution by freeze-drying or vacuum drying U.S. Pat. No. 4,371,516(Examined Japanese Patent Application Publication (Kokoku) No. 62(1987)-50445), (W/O 93/12769)(Publication of Translations of International Patent Application. No. 5-812769)!. This method, however, has problems in that it takes time for manufacturing and in that the obtained products have insufficient strength and thus are difficult to handle. There is known another method in which a mixture of a pharmaceutically active ingredient with a low moldability saccharide is granulated with a high moldability saccharide added thereto EPA 745382, (Publication of Translations of International Patent Application No. 7-820380 (WO 95/20380))!. The product obtained by this method has such hardness that the dosage form remains without being disintegrated in the course of distribution, while the method has a problem that tabletting is not easy, as is often the case with high moldability saccharides, because tabletting is carried out with lower pressure. Also the products have an additional defect that they leave a problem to be solved in terms of buccal fast disintegration and dissolution. On the other hand, studies have been made of buccal dissolution preparations produced by wetting molding. But, in general, tablets having fast disintegration or dissolution have defects of lack in strength.
From the foregoing view-point, there is a need or demand for development of preparations which exhibit excellent buccal disintegration and dissolution and also an appropriate strength such that the preparations never disintegrate or suffer damage in the course of the production steps or distribution stages. Japanese Patent Applications Laid-open Nos. 1-268627, 1-268628 and 8-27033 describe a pharmaceutical preparation or composition containing erythritol, but fail to describe intrabuccal dissolution type preparations.
This invention provides solid pharmaceutical preparations which can be readily administered even without water, especially solid pharmaceutical preparations which quickly disintegrate and dissolve in the oral cavity.